Sound-wave-intensifying device for reproducers



Jan. 26 1926.

A. WYATT SOUND WAVE INTENSIFYING DEVICE FOR REPRODUCER Filed April 10, 1922 www Patented Jan. 26, 1926.

UNITED sTATEs PATENT OFFICE.

ALFRED WYATT, 0F KANSASCITY, MISIE'JUBI, ASSIGNOB 0F ONE-THIRD TO lSAMUEL '.T. COCHRAN AND ONE-THIRD TO FRANK A. COCHRAN, BOTH OF KANSAS CITY,

, MISSOURI.

Appiieatien mea Aprii 1o, i922. semina. 550,991.

To all whom t may concern;

Be it known that I, ALFRED VVYATT, a citizen of the United States, and resident of Kansas City, county of Jackson, State of Missouri, have' invented a certain new and useful Improvement in Sound-Wave-Intenf sifyin Devices for -Reproducers, of which the fo lowing is a complete specification.

This invention relates to combined reroducers and microphone attachments and is designed to furnish a device whereby mechanical vibrations such as those producedby thediaphragm of a phonograph ieproducer, may be changed into electrical vibrations for transmissionl by metallic or wireless circuits and fin'ally reproduced by any suitable mechanism.

One of the objects of the invention is to produce a device of this character in which the microphone attachment is so coupled to the reproducer that practically the full force of the vibratory movements of the reproducer diaphragm are transmitted to the microphone.

Another object is to produce a device of the character set forth which is compact and of simple, durable, efficient and ine-X- pensive construction: and in order that it may be fully understood, reference is to be had to the accompanying drawing, in which:

Figure 1 is a face view of the device;

Figure 2 is an edge view of the same;

Figure 3 is a section on the line III-III of Figure 1;

Figure 4 is an enlarged central vertical section through the microphone; and

Figure 5 is a vertical section taken through a modified form of the device.

In the said drawing, where like reference characters identify corresponding parts in all of the figures, 1 represents al cylindrical casing of any suitable material, closed at one end except for a relatively small opening 2, and openat its other or rear end. The open end of the casing is closed by a flanged closure 3 formed with an opening 4, the flanged edges of such closure overlapping the edges of the casing 1, and being held in this position by means of suitable screws 4 engaging the edge of the casing 1.

The casing 1 is supported by means of a tubular arm 6 secured by means of screws 5 to the closure 3, and communicates at its opposite end with a hinged member 7 to.

VReceived within the flanged recess formed by the. flange 10 is a disc 11 of metal of any suitable character, and retained in position by means of 'a series of screws 12 engaging the flange 10 of the ring 9 (see F igure'3).

The disc 11 is provided centrally with a threaded opening in which the threaded stem 12 of a microphone casing 13 is screwed. The microphone may be of any common and well known type, and, as illustrated, comprises the casing 13 which is internally threaded for the reception of a flanged sleeve 14, retaining in position a diaphragm 15 of mica or the like. Secured to said diaphragm for the transmission of vibration thereto is a metal disc 16 which is'formed with a threaded stem passing through the mica diaphragm and engaged at the opposite or inner side of the mica diaphragm with a hard carbon disc 17, the chamber thus formed having its .opposite end covered with a second hard carbon disc 18 closely abutting the casing 13 and the side wall being encircled by a mica ring 19, the space between said discs 17 and 18 being partially filled with the customary carbon granules 20. As the microphone is of common and well-known construction. it is not thought necessary detail the operation .thereof in performing its function of increasing or diminishing the resistance to the sary vibration, a rubber or other suitable washer or ring 2.4 is interposed between the closed end of the casing and said diaphragm, a further important function for this ring 24 being to protect the diaphragm 22 from the metallic sounds of the reproducer de- Nice.

In order to provide means for attaching the reproducer of the casing land leave the diaphragm 22 connected to the microphone free for vibration, the closure of the casing is pressed slightly outwardly, and adapted to be secured to the said closure is a flanged casing 25 held in position by means of screws 26 engaged with casing 1, and interposed between said members is a washer 27, of rubber or the like, adapted to cooperate with the ring 24 in preventing the transmission of metallic sounds to the mlcrophone casing, as will be readily understood.

The casing 25 is adapted to receive a retaining ring 28 held in position by means of a series of screws 29, and said ring retains in position a mica or similar reproducing diaphragm 30, with its mounting 31, as common and well-known in the art. the center of the diaphra m 30 is a vibrating arm 32, attached at its lower end to a phonograph needle carrying-device 33 as common in phonograph construction.

In order to complete the electrical circuit through the microphone, a bindin post 34 is secured to the disc 11, and a con uctor 35, is connected to said binding post which forms a part of a suitable electrical circuit. The other terminal of the microphone, the disk 18, is connected by a suitable conductor 36 to a binding post 37, carried by and suitably insulated from the disc 11, as shown at 38. Exteriorly of the casing a conductor 40 is connected to said binding post 37 and forms a part of the same circuit as the conductor 35. The mode of operation of the microphone will be clearly understood by one skilled in the art, and it is not thought necessary, therefore, to detail the manner in which the carbon granules will vary the resistance in the circuit.

When the device is in operation it will be evident that the diaphragm 30 will be vibrated in accordance with the movement of the phonograph needle in4 the playing grooves of the record, and that these vibrations Will be mechanically transmitted to the diaphragm 22 with but little, if any loss of intensity due to the proximity of the diaphragms to each other and their direct connection. As the diaphragm 22 is directly connected to the stem 21 of the microphone diaphragm 15, the latter will be subjected to practically the full vibratory force received by diaphragm 22 and the vibrations thereof will be immediately transmitted electrically over the electric circuit with vastly increased intensity, in response to the well-understood action of the microphone device. Moreover,

Secured to the direct association of the microphone with the reproducer as shown enables themicrophone to absorb all the most important vibrations which would otherwise be lost, and to transmit such sound volume in f ull to the point of reproduction.

In Figure 5, a modified type of device is illustrated in whicha plurality of microphones 13 are employed, two only being illustrated. This modified form w1ll function in every way similar to that of the single type above-described, but it is desirable to state in this connection that each of the microphones must be connected to the diaphragm 22 at equal distances from the center thereof, in order that each of the microphones Will be subjected to equal vibrations, as will be readily understood. It will be evident that wherea plurality of microphones are employed, there will bel a greater intensity of the vibrations transmitted over the electric circuit in response to the vibrations of diaphragm 22, and that for this'reason the receiving instrument will emit correspondingly stronger sound waves with increased volume of the tones or sounds being reproduced.

From the above description it will be apparent that I have produced a device of the character described, which possesses all of the features of advantage set forth as desirable, and while I have described and claimed the preferred embodiment of the same, I reserve the right to make all changes properly falling within the spirit and scope of the appended claims.

I claim:

1. In a device of the character described, the combination with a casing provided with an opening at one of its ends, of a microphone carried within said casing, a diaphragm in said casing having its center substantially alined with respect to the axis of said casing-opening and being mechanically connected to said microphone so that vibration of tle diaphragm shall be transmitted tothe microphone diaphragm, means interposed between the opening-provided end of said casing and the edges of the diaphragm for cushioning same against metallic noises, a second casing secured to said lirst-named casing and provided with an opening registering with the opening in said first-named casing, means interposed between said casings for preventing the transmission of metallic noises, a second diaphragm within said second casing and having its center substantially alined with the axis of the casingopening, and means for effecting vibration of said second diaphragm.

2. In a device of the character described, the combination of a casing having an opening in one of its ends, a recessed insulating disc fitting within said casing, a conducting disc secured within the recess of said insulating dise, a microphone carried by said named casing, a second diaphragm in Said conducting disc, a diaphragm in said casing second easing in axial alinement with the operatively connected to said microphone opening thereof, and means for effecting vi- 10 and in axial alinement with the casing openbration of said second diaphragm.

ing, a second casing secured to said rst- In Witness whereof I hereunto afix my named casing and having an opening in axial signature.

alinement with the opening of said rst- ALFRED WYATT. 

